In some conventional cleaning devices of this kind as disclosed in JP 2002-229344 A, an intermediate transfer belt as an image carrier is brought into contact with conductive first cleaning brush and second cleaning brush, and the first cleaning blush is provided with a bias with a polarity (e.g., negative voltage) opposite to the charged polarity (positive polarity in this example) of most of the residual toner on the intermediate transfer belt, while the second cleaning brush is provided with a bias (positive voltage in this example) with the same polarity as the charged polarity of the most of the residual toner. In this cleaning device, most of the residual toner on the intermediate transfer belt is first electrostatically attracted to and cleaned by the first cleaning brush. A small quantity of the opposite polarity toner which was not cleaned by the first cleaning brush is then electrostatically attracted to and cleaned by the second cleaning brush placed downstream from the first cleaning brush.